It is controlled by the company so you have to wait for sales. Someone just told me she called the company and they put her on their e-mail list.
I get their e-mails too and that is the only time I buy. The last time they had a special buy 3 and get 1 free what came down to $28.45 per bottle. I sold 2 to CZ members for my cost.
You could look into colosan (google) that might be cheaper.